Safety mechanism for elevators



C. P. BEAVER. SAFETY MECHANISM FOR ELEVATORS.

APPLICATION FILED ocr. 20, 1919.

1,348,201. PatentedAug. 3,1920.

2 SHEETSSHEET I.

rrrrrrr wvw Elmuemtoz C. P. BEAVER.

SAFETY MECHANISM FOR ELEVATORS.

0 9 IT w m dw W2 D m a P 0U m 0 2 m 0 D H N O .H A w H P A 1 0 2 8 4 3 1avwzmtoz Car/ l fieayer- UNITED STATES PATEN OFFICE:

CARLHPOSEY BEAVER; or DUCKTOWN, TENNESSEE.

1 '0 all whom it may concern:

7 Be it-knowng that I, CARL. Poser BEAVER,

a citizen of-the United .States, residingat Ducktown, in the county ofPolk, State of Tennessee, have invented certain? new and usefulImprovements in Safety Mechanism for Elevators; and-I do hereby declarethe following to be a full, clear,--and= exact description of theinvention, suchaswill; enable others skilled in the art to which itappertains to make and use the same.

This invention relates to safety devices for elevators. V

The object of the invention is to improve the structure of safetydevices for elevators, the improvements being wroughtin that type ofsafety devices; in, which the safety clutch members or-stops are-zheldout: of engagement When the elevator cage is suspended from the oablebut, are released into, stopping position when the cable breaksso thattheweight of the cage is not carriedthereby. The invention: resides,jnot only inthe provision of. the improved clutch releasing mechanism,but in the clutch members themselves and the manner in which they aremountedi';

With the above objects, view, and -such ence being had to theaccompanying, draw-,

ing's. V EI-n the drawings: 1 I 1 Figure 1 is anwelevation disclosing;the general assemblage of the mechanism, f

' Fig. 2 is a ,verticalsection'on line 2 2} of Fig.1, v

Fig. 3 is a section on line 33-of Fig.1,- 7 qFig; his a section; on line44 of Fig. 1, Fig. 5-' is.a' section similar to Fig. 4, but showingthe-partsin closed position,

Fig. '6 is an enlarged d etailperspective view, 7 1

Fig; 7 is a further detailv-iew' and- ;Fjg- 8 is another detail view.Referring more particularly to; the drawings, 1 represents the railsupon-which the cage 20f aimine elevator operates. The cage;2;may:operatezin either a vertical or an in- -clined shaft, but theelevator construction in the present instance, is thatwhichisparticularly adapted for usein inclined shafts.

-.'l"herefore,-tlie car-2 is supported unonythe rails: 1 by;-: means ofcmllersvor'. nheels Specification of Letters'r'atent.

, p Patented Aug. 3, 1920;-

Application filed October 20,1919. sena1-no. 3s1,s22. i

Mounted upon the side of the car which 7 spans 'the railsl is a rackbar4 whichds longitudinally movable, to a limited degree, within guldemembers 5 secured-to the'car or. cagebody. Thelower end of the1 rack barlis connectedto one end of a, comparatively. heavy spring 6 whoseopposite endi-is is provided togwhichthe elevator cable; 11

is; secured. I The tendency of the cablel l, when it is tensioned'tolift the-cage, ,isto draw; therack bar upwardly against the tension otthe spring 6 until a balance ofj the forces has beenSiZIIICk.K.MO11IltBd ind-outer brackets on bearings secured tothe sideof thecage 1s a-shaft12 which extends transyersely of the rack bar-4and-has-arpinion "13 which meshes with the teeth'oftherack bar... Alsomounted upon theshaft 12-;are the worms 1 1 which mesh withwor'm gears 15 mounted upon the upper endsof the shafts 16. S;aiclw shafts 16 arecarried in bearings 17 :disposed at. practically equal; distances theshafts 16 substantially parallel the-latter. Surrounding the shafts 1 6are; the; coil springs 18; ,Preferably, there .are .-two

springs to each shaft, one endof each o? the springs being: connected toits respective from opposite sides of the rack .bar,-.so that I shaftand the; opposite endbeingfixed to-ene ofthe brackets or bearings 17 ror to another bracket secured to the side of; the cage. The tendency ofthe springs is to turn theshafts r ta ion imparted b WQPmI gears 15.-

the -.vvonns- 14 ,to the secured in a suitable manner to the side ,of

- 16 me direction-oppositeto the directionof the cage2 aretheshorizontailly or trans versely s-lidable clutch :frames-20eand-21upon which are formed the clutch elements 22 and23 respectively,v theclutch members 22 being adapted to grip the inner sides-pf the railsvwhile'the clutchmemfbers 23 are oppositely disposed-to; clutch theoutersides of the rails opposite. the members 22. The clutch members 22 and23,1n'ay; havefgripping 'faces of any suitable form, .series of ts h beeg. nd ated v lat napins ein t nc for taking hold of the faces of thesides of the rails. The clutch frames 20' and 21 are connected in pairsto the shafts 16 by'mean's of the devices which tend to throw themelnbersof the pairs in opposite directionsiso to close or open themsimultal ieously,

Thus, upon eachof the shafts 16 there are secured sets of eccentrics24l-and'25. The eccentrics 24 extend inwardly from the shafts, withrespectto the rails, and are s'ur+ rounded by eccentric straps 26carried by the frames 20 so that rotation of the "shaft 16 tends tothrow the fram'es'20 outwardly. The sets of eccentrics '25extend'outwardly orin the opposite direction from the eccentries 24, sothat as the shafts 16 are rotated, eccentric straps- 27 which arecarried by the frames 21 and surround the eccentrics tend to drawtheclutch members 23 inwardly into engagement with the railssimultaneously. with the outward-movement of theclutchmembers 22.

' In-the use of'the clutch mechanism which has been described, the parts'are held in a normally inoperative position by the tension of theweight of the cage which is suspended from the cable 11, since theupward pull of I the cable lifts'the lever 8 and'with it the rack bar4'; When'the'rack bar 4' is lifted,

the'pini'on 13 isfrotated to operate the worms 5 '14 with result thatthe shafts .16 are rotated against the tension of the springs 18. Thisrotation of the shafts 16 separates the clutch.

members 22 and 23 sothat they clear the rails. The lift of the cable 11draws the rack bar 4 upwardly against the tension of the spring 6,'; othat when the cable 11' is untensioned or broken, the spring 6immediately draws the rack bar downwardly into its normal position,withthe result that the shafts "16 are 'released to the tension of thesprings 18, and are also aided in their return rotation by the motioncommunicated to the rack-bar through the gears 13,14 andf 15. "Theimmediate result 'of this action is to throw the clutch members 22 and23 into enjgagementwithjthe rails so that the car is 'stopped'f thereby"within a few inches of travel; i I i It will be apparent from theforegoing description that the elutchmechanism constitutes a very simplegripping means for stoppin'g a ear or cage" lafterfits 'lioisting cableshave par-tedgand that furthermore the mechanism inadditionfto itssimplicity, w'ill'act positively and with sufficient strength to stopthe car even though the latter were "traveling with considerablemomentum at the time the break occurred; q 'VVhat "*I claim as minvention, is

1. Asafetym'echamsm forele'vators, comprisinga longitudinally movablerack bar, a pair of shafts paralleling said rack bar, means gearing saidrack bar to the shafts,

to" rotatethe latter, clutch members are ranged to grip the elevatorrails, and means operated by the rotation of the shafts to close the'elutch'members'over the rails;

2. A safety mechanism for elevators, comprising a longitudinally movablerack bar, a pair of shafts paralleling said rack bar, means gearing saidrack bar to the shafts to rotate the latter, clutch members arranged togrip the elevator rails, and means pivotally supporting the clutchmembers on the shafts'in such relation that'rotat'ion of the lattercloses the clutch members Onythe rails. i 3. A safety mechanism forelevators, comprising a longitudinally movable rack bar, a pair ofshafts paralleling said rack bar, means" gearing said rack bar; to theshafts to rotate the latter, clutch members arranged to grip theelevator rails, and' eccentric supports on the shafts and carrying theclutch members so that; rotation of the former closes the latter on therails. 1 4. A safety mechanismfor elevators, comprising a longitudinally'movable'membena to rotate the latter, clutch ;mem'bers' arranged togrip the elevator rails, and means operated-by the rotation of theshafts =to close the clutch members over the rails. I 5; A safetymechanism for; elevators, comprising a longitudinally movable 'member, apair of shafts paralleling said member,

means connecting said memberto the shafts to rotate the latter, clutch'members arranged to grip the elevator rails, and 'means supporting theclutchmembers on'the shafts insuch relation that rotation of the latter'closesthe clutch members on the rails;

6. 'A- safety mechanism for elevators, comprising a longitudinallymovable member, a pair of shafts paralleling said member, meansconnecting said member to the'shafts to rotate the latter, clutchmembers arranged-to grip'the elevator rails-and eccentric supports onthe shafts and carrying the clutch members so that rotation of; theformer closes the latter on the rails.

7 A safetymechanism for" elevators, comprising in combination, alongitudinally movable member, a means normally holding said member atone limit of its movement,

means to connect a hoisting cable to the member tomove thel'atteragainstsaid-hold 5 ing means, a pair of shafts paralleling the 'Inovablemember, means gearing said memv 'be'r'to the shafts to rotate the latterwhen it is longitudinally moved, and clutch mem- "bers arranged'to gripthe elevator rails and connected to the "shafts toclosef-when thetension of the cable is released to permit the return fof the member tonormal position.

- 8; A safety mechanism for elevators, comprising in combination, alongitudinally mov'able member, ameansnorma'lly holding said member atone limit of its movement,

means to connect a hoisting cable to the 10 sion of the cable isreleased to permit the return of the member to normal position,

7 and resilient means normally tending to 1'0- tate the shafts intoclutch opening position.

In testimony whereof, I afiix my signature in the presence of twowitnesses.

CARL POSEY 2 BEAVER.

mark Witnesses:

H. W. BERRYMAN, H. C. WHrrL'ooK.

